1. Field of the Invention
This invention relates to apparatus including a housing and a disposable film processing kit for processing an exposed roll of instant type transparency film.
2. Description of the Prior Art
The present invention relates to apparatus for processing, i.e., producing visible images, an exposed roll of self-developing or instant type transparency film, preferably of the type which is adapted for use in conventional 35 mm cameras, vis-a-vis self-developing or instant type cameras. More specifically, the apparatus includes a disposable processing kit which is adapted to be placed as is, into a housing which, in turn, is also adapted to locate an exposed roll of 35 mm film in position such that the film may be driven into the kit and wound upon a drum in superposition with a length of sheet material having a gel coated surface. Prior to superposing the film and sheet material, a layer of processing composition is coated on the sheet material. The film and sheet material remain coiled on the drum with the layer of processing composition therebetween until the latent images in the film have been substantially developed. Thereafter, the film is stripped from the sheet material and directed to the exterior of the apparatus where it may then be cut and mounted in suitable frames for subsequent use in a viewer and/or projector.
Broadly, the concept of providing apparatus for developing an exposed roll of instant type transparency film of the type adapted for use in conventional 35 mm cameras is disclosed in U.S. Pat. Nos. 4,167,318 and 4,200,383 and on pages 132-134 of RESEARCH DISCLOSURE, dated April, 1980 .
The film assemblages disclosed in the RESEARCH DISCLOSURE article basically include a cylindrically shaped film cassette, a supply of instant type transparency film, and a supply of processing composition located within the film cassette. The film in these assemblages is adapted to be processed in apparatus taking the form of a conventional 35 mm camera in which the film was exposed. After the film has been almost totally withdrawn from the film cassette during the exposure thereof, it is rewound into the film cassette and during such rewinding, a container (or a plurality of containers) of the processing composition is ruptured by a lip located adjacent to the film withdrawal slot in the cassette and its contents spread between superposed sheets of the film. Disadvantages with these types of film assemblages are many and include (1) a limit on the length of film that may be wound within the film cassette due to the volume occupied by the processing composition, (2) the shelf life of the assemblage is a function of the shelf life of the film or that of the processing liquid, whichever is the shorter, vis-a-vis an assemblage which does not contain the processing composition as a part thereof, and (3) an additional limit is placed upon the length of film that may be accommodated by the cassette because the film is apparently comprised of two lengths of superposed film.
The apparatus disclosed in U.S. Pat. No. 4,167,318 includes a pair of sprocket wheels, the projections of which are adapted to enter the sprocket holes in the film being processed. If, for any reason, one of the projections should not enter a sprocket hole in the film during advancement of the film, it is possible that the film may be damaged. For example, if a projection were to move into engagement with the film at a point intermediate two sprocket holes, it may penetrate the film and cause a laterally extending tear in the film, or it may raise the film such that it becomes partially or totally disengaged from the associated sprocket wheel. Further, the apparatus disclosed in U.S. Pat. No. 4,167,318, as well as that disclosed in U.S. Pat. No. 4,200,383, is not adapted to strip the layer of film containing the processed positive visible image of the transparency from the remainder of the film structure. Accordingly, the finished product is one in which a greater amount of light must be directed through the transparency in order to get a projected image having an illumination equal to that wherein the transparency does not include the emulsion layer and/or residual processing composition.
U.S. Pat. No. 2,880,657 shows apparatus in the form of a camera-projector which is provided with means for processing an exposed photosensitive sheet by superposing the photosensitive sheet with a second sheet and spreading a thin layer of processing composition between the superposed sheets as they are being wound upon a rotating drum. The photosensitive and second sheets are maintained upon the drum in superposition with the layer of processing composition interposed therebetween for a predetermined processing period during which visible images are produced in one of the sheets, preferably in the second sheet. At the end of this predetermined period of time, the second sheet is stripped from the photosensitive sheet, advanced past a projector such that the images therein may be viewed, and then wound upon a take-up spool. However, this apparatus does not lend itself to the processing of 35 mm instant type film, which film is packed in film cassettes which are adapted to be exposed outside the processing apparatus, i.e., in conventional 35 mm cameras.